The present invention relates generally to refrigerant recovery systems and, more specifically, to a refrigerant disposal system useful in connection with a refrigerant recovery system for the on-site destruction of recovered refrigerants. The refrigerant disposal system is suitable for use with conventional refrigerant recovery systems whether the refrigerant is recovered as a vapor or a liquid.
A wide variety of mechanical refrigeration systems are currently in use in a wide variety of applications, such as, for example, domestic refrigeration, commercial refrigeration, air conditioning, dehumidifying, food freezing, cooling and manufacturing processes, and numerous other applications. The vast majority of mechanical refrigeration systems operate according to similar, well known principals, employing a closed-loop fluid circuit through which a refrigerant flows. Those familiar with mechanical refrigeration systems will recognize that such systems periodically require service. Such service may include removal, of, and replacement or repair of, a component of the system. Further during normal system operation the refrigerant can become contaminated by foreign matter within the refrigeration circuit, or by excess moisture in the system. The presence of excess moisture can cause ice formation in the expansion valves and capillary tubes, corrosion of metal, copper plating and chemical damage to insulation in hermetic compressors. Acid can be present due to motor burn out which is caused by overheating of the refrigerant. Such burn outs can be temporary or localized in nature as in the case of a friction producing chip which produces a local hot spot which overheats the refrigerant. The main acids of concern are HCl and HF, but other acids and contaminants can be produced as the decomposition products of oil, insulation, varnish, gaskets and adhesives. Such contamination may lead to component failure or it may be desirable to change the refrigerant to improve the operating efficiency of the system.
When servicing a refrigeration system it is necessary to vent the refrigerant from the system before the components of the system are serviced and repaired. However, older refrigeration systems typically use chlorofluorocarbon compounds (CFCs), such as R-11 and R-12, which are believed to have an adverse impact on stratospheric ozone. More recently, refrigeration systems are being marketed that use hydrochlorofluorocarbons (HCFCs), such as R-22 and R-123, and hydrofluorocarbons (HFCs) which, although considered to have little or no impact on stratospheric ozone, are believed to contribute to possible global warming, owing to their relatively long atmospheric lifetimes. Thus, it is no longer considered environmentally acceptable to vent any type of refrigerant to the atmosphere from refrigeration systems containing such conventional refrigerants.
Accordingly, systems have been provided that are designed to recover the refrigerant from refrigeration systems. Representative examples of conventional refrigerant recovery systems are shown in the following U.S. Pat. Nos. 4,441,330 to Lower et al for "Refrigerant Recovery And Recharging System"; 4,476,688 to Goddard for "Refrigerant Recovery And Purification System"; 4,766,733 to Scuderi for "Refrigerant Reclamation And Charging Unit"; 4,809,520 to Manz et al for "Refrigerant Recovery And Purification System"; 4,862,699 to Lounis for "Method And Apparatus For Recovering, Purifying and Separating Refrigerant From Its Lubricant"; 4,903,499 to Merritt for "Refrigerant Recovery System"; 4,942,741 to Hancock et al for "Refrigerant Recovery Device"; 5,127,232 to Paige et al for "Method And Apparatus For Recovering And Purifying Refrigeranf"; 5,146,760 to Paige for "Method And Apparatus For Compressor Protection In A Refrigerant Recovery System"; 5,146,761 to Cavanaugh et al for "Method And Apparatus For Recovering Refrigerant"; 5,174,124 to Paige et al for "Apparatus For Sampling The Purity Of Refrigerant Flowing Through A Refrigeration Circuit"; 5,181,390 to Cavanaugh et al for "Manually Operated Refrigerant Recovery Apparatus"; 5,243,828 to Paige et al for "Control System For Compressor Protection In A Manually Operated Refrigerant Recovery Apparatus"; 5,247,804 to Paige et al for "Method And Apparatus For Recovering And Purifying Refrigerant Including Liquid Recovery"; and 5,255,527 to Paige for "Method Of Testing The Purity Of Refrigerant Flowing Through A Refrigeration System".
In conventional refrigerant recovery systems such as for example the systems disclosed in the aforementioned patents, the refrigerant vented from the refrigeration system is condensed and collected in a storage tank. If the particular refrigerant collected is of the class of refrigerants now considered environmentally unacceptable, the refrigerant storage tank is sealed, removed from the recovery system and sent to a processing center for destruction. At the processing center, the refrigerant is treated, for example by incineration, high temperature oxidative reactions, catalyzed chemical reduction, reaction/reduction with solvated electrons, or biodegradation in either anaerobic or aerobic environments, to decompose the refrigerant into environmentally benign products. While suitable for large batch treatment of refrigerants at large processing centers, such treatment strategies are not optimum for use for small batch processing of recovered refrigerants on-site at the location of the refrigeration system from which the refrigerant was recovered. On-site disposal of recovered refrigerant would avoid the transportation and handling costs associated with removal of the recovered refrigerant to an off-site processing center. On-site disposal of recovered refrigerant in an environmentally acceptable manner would also be particularly advantageous for use in connection with mobile air conditioning units, transportation refrigeration units, residential air conditioners and smaller commercial air conditioning or refrigeration installations.